Phil Goff mocks John Tamihere's 'dumb' Watercare part-privitisation plan

The battle to become the next Mayor of Auckland has become a clash of ideas about how to clean up the city's beaches.

Incumbent Mayor Phil Goff says John Tamihere's idea to sell off a stake in Watercare is "dumb" - but Tamihere insists he has high-level support behind the plan.

Even an event to mark the five-year rebuild of one of Auckland's most iconic roads turned to talk of the city's beaches on Wednesday.

"It was going to take 30 years to clean up our beaches, we're going to do it in less than 10," Goff said.

A revamped Franklin road includes a Watercare project to separate waste and stormwater pipes to stop sewage overflow into the Waitemata Harbour.

But Goff's rival mayoral candidate John Tamihere wants to sell off 49 percent of Watercare. He says that would raise $4 billion and part of that would be used to fix 29 beaches unfit for swimming this year.

"I heard that he was thinking of doing that but I thought it was such a dumb idea that he'd never carry it out," Goff said.

Goff says it would push up water rates by $200 to $300 and would hit large families hardest. But Tamihere says that would be balanced out by removing petrol taxes.

"You've got to smooth the pain. This part-sale smoothes the pain, Goff just whacks you over the head with more rates," he says.

Tamihere says both the New Zealand superannuation fund and ACC investment funds have shown interest in his proposal to sell part of Watercare. Goff isn't convinced.

"That's misleading and deceitful - I checked with ACC, they hadn't heard of it," he says.

But Tamihere insists it's true.

"He's welcome to say what he says. I've met with folk who are interested in doing this," he says.

However he wouldn't name who these "folk" are.

"That's my business and their business but you can go and ask  ACC whether they'd see it as a worthy investment."

Newshub did ask ACC exactly that. Their response was that they have not received any investment proposal nor are they aware of any sales process.

So as to their interest in it, that's neither a yes or a no. Auckland residents will be asked to pick a side in the October mayoral election.